Phillip Susi <phill@xxxxxxxxxxxx> writes: > I just formatted a clean fs, synced, and ran blktrace, then synced > again, and only ext4 emits a flush on the second sync. Just to clarify, I waited for the ext4 lazy itable init to finish, then after that, every time you sync, you get another flush, even though there has been no write. That's what I'm trying to get rid of. This flush with no writes keeps waking up my media/archive disks when I shutdown or suspend to ram. At least it does now that I am trying to use runtime_pm instead of hdparm -y or hdparm -S.
